/* Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.activiti.rest.common.api;

import org.activiti.engine.ActivitiIllegalArgumentException;
import org.activiti.engine.impl.AbstractQuery;
import org.activiti.engine.query.Query;
import org.activiti.engine.query.QueryProperty;

import java.util.List;
import java.util.Map;

/**
 * @author Tijs Rademakers
 */
public abstract class AbstractPaginateList {

    /**
     * uses the pagination parameters form the request and makes sure to order the result and set all pagination
     * attributes for the response to render
     *
     * @param req         The request containing the pagination parameters
     * @param query       The query to get the paged list from
     * @param listName    The name model attribute name to use for the result list
     * @param model       The model to put the list and the pagination attributes in
     * @param defaultSort THe default sort column (the rest attribute) that later will be mapped to an internal engine name
     */
    @SuppressWarnings("rawtypes")
    public DataResponse paginateList(Map<String, String> requestParams, PaginateRequest paginateRequest, Query query,
                                     String defaultSort, Map<String, QueryProperty> properties) {

        if (paginateRequest == null) {
            paginateRequest = new PaginateRequest();
        }

        // In case pagination request is incomplete, fill with values found in URL if possible
        if (paginateRequest.getStart() == null) {
            paginateRequest.setStart(RequestUtil.getInteger(requestParams, "start", 0));
        }

        if (paginateRequest.getSize() == null) {
            paginateRequest.setSize(RequestUtil.getInteger(requestParams, "size", 10));
        }

        if (paginateRequest.getOrder() == null) {
            paginateRequest.setOrder(requestParams.get("order"));
        }

        if (paginateRequest.getSort() == null) {
            paginateRequest.setSort(requestParams.get("sort"));
        }

        // Use defaults for paging, if not set in the PaginationRequest, nor in the URL
        Integer start = paginateRequest.getStart();
        if (start == null || start < 0) {
            start = 0;
        }

        Integer size = paginateRequest.getSize();
        if (size == null || size < 0) {
            size = 10;
        }

        String sort = paginateRequest.getSort();
        if (sort == null) {
            sort = defaultSort;
        }
        String order = paginateRequest.getOrder();
        if (order == null) {
            order = "asc";
        }

        // Sort order
        if (sort != null && !properties.isEmpty()) {
            QueryProperty qp = properties.get(sort);
            if (qp == null) {
                throw new ActivitiIllegalArgumentException("Value for param 'sort' is not valid, '" + sort + "' is not a valid property");
            }
            ((AbstractQuery) query).orderBy(qp);
            if (order.equals("asc")) {
                query.asc();
            } else if (order.equals("desc")) {
                query.desc();
            } else {
                throw new ActivitiIllegalArgumentException("Value for param 'order' is not valid : '" + order + "', must be 'asc' or 'desc'");
            }
        }

        // Get result and set pagination parameters
        List list = processList(query.listPage(start, size));
        DataResponse response = new DataResponse();
        response.setStart(start);
        response.setSize(list.size());
        response.setSort(sort);
        response.setOrder(order);
        response.setTotal(query.count());
        response.setData(list);
        return response;
    }


    /**
     * uses the pagination parameters from the request and makes sure to order the result and set all pagination
     * attributes for the response to render
     *
     * @param req         The request containing the pagination parameters
     * @param query       The query to get the paged list from
     * @param listName    The name model attribute name to use for the result list
     * @param model       The model to put the list and the pagination attributes in
     * @param defaultSort THe default sort column (the rest attribute) that later will be mapped to an internal engine name
     */
    @SuppressWarnings("rawtypes")
    public DataResponse paginateList(Map<String, String> requestParams, Query query,
                                     String defaultSort, Map<String, QueryProperty> properties) {
        return paginateList(requestParams, null, query, defaultSort, properties);
    }

    @SuppressWarnings("rawtypes")
    protected abstract List processList(List list);
}
